Fastener



July 17, 1962 E. B. FERNBERG 3,044,809

FASTENER Filed May 18, 1959 INVENTOR ERIC BIRGER FERNBERG BY wwwg wvATTORNE Y United States Patent 3,044,809 FASTENER Eric Birger Fernherg,Northwootl, England, assignor to RT. Products Limited, London, England,a British company Filed May 18, 1959, Ser. No. 813,839 Claims priority,application Great Britain Dec. 12, 1956 1 Claim. (Cl. 287-53) Thepresent invention relates to an improved fastener for releasablysecuring together male and female members such as a shaft with a flat onit to a knob formed with a stopped bore for the reception of the shaft.

This application is a continuation in part of my copending application702,053 filed December 11, 1957.

In my co-pending application No. 702,053 there is described and claimeda fastener comprising a flat strip of spring material bent so as to haveat least a portion of its length in approximately U- or horseshoe-shapewith a web and two limbs, there being formed in one limb of thehorseshoe at least one prong having its free end directed outwardly withrespect to the horseshoe, said prong being sharply pointed and havingits point bent out of the general plane of the material surrounding theprong.

There is also described and claimed in my co-pending application anassembly of male and female parts secured together with the aid of afastener as defined in the previous paragraph, wherein the male part isin the formlof a shaft with a flat on it, all cross sections of theshaft being segments of a circle, the female member is formed with alongitudinally extending bore of shape preventing movement of the shafttransversed through its axis, and with a recess which opens into thebore and has at least one wall disposed closer to the axis of the shaftthan the flat and serving to reduce the size of the opening in the boreand the recess, the fastener being located in the recess so that itspronged limb engages a wall thereof so as to prevent the fastener comingout of the recess and its other limb extends through the opening andbears resiliently against the flat on the shaft.

It is an object of the present invention to provide a fastener of thekind described above for use in an assembly described above so formed asto have a greater resilience.

According to the present invention there is provided a fastenercomprising a flat strip of spring material bent so as to have at least aportion of its length in horseshoeshape with a web and two limbs, therebeing formed in one limb at least one sharply pointed prong having itspoint bent out of the general plane of the material surrounding theprong so as to be directed outwardly with respect to the horse-shoeshaped fastener, wherein the length of the prong from its root to itsfree end is at least one quarter of the length of the major axis of thehorse shoe.

A preferred form of the invention will now be described with referenceto drawing, in which:

FIGURES 1, 2 and 3 are respectively a plan view, side elevation and rearview of a fastener,

FIGURE 4 is a sectional elevation of a shaft assembled in a bore in aknob with the aid of the fastener of the FIG- URES 1-3, and

FIGURE 5 is a side elevation of an alternate form of fastener.

The fastener, generally indicated at in FIGURES 1 to 3, is similar tothe fastener described in my co-pending V "ice - 2 application SerialNo. 702,053 of which this application is a continuation in part, exceptthat the prongs 11, 11A are longer and, in this case, square-nosed. Eachprong 11, 11A thus acts in the manner of a leaf spring and adds itsresilience to that of the fastener as a whole.

During manufacture, areas 12, 12A (FIGURE 3) have been cut away from thesides of the fastener and parallel shear cuts 13, 13A, extending fromthe inner edges of the cut away areas approximately vparallel with thesize of the fastener, have been made so as to provide square-nosedprongs 11, 11A, the length of which from their root 16 or 16A to theirfree end is at least or one quarter of the height, or major axis (x,FIGURE 2), of the fastener.

In FIGURE 4 are illustrated a knob 14 and a shaft 15 similar to thoseillustrated in FIGURES 6 to 10 of the drawings of my application No.702,053 of which this application is a continuation in part. Thefastener 10 lodges within the recess in the knob and engages the flat onthe shaft to releasably secure the knob and shaft together in the mannerdescribed in connection with the fastener of our co-pending applicationabove referred to.

The outwardly bent free ends of the prongs 11, 11A press against theouter vertical wall of the recess to prevent the fastener 10 falling outof the knob if the knob is pulled off the shaft, and due to their lengthand shape give both greater strength and resiliency to the assembly as awhole.

The free ends of the prongs may if desired be pointed to give added gripon the walls of the recess.

FIGURE 2 shows a fastener in which the free end of the pronged limb ofthe horseshoe shape is extended and bent to be adjacent the inside ofthe other limb. On the other hand FIGURE 5 shows an alternate fastenerin which the extension of the pronged limb is bent to be adjacent theoutside of the other limb.

Many of the fasteners described in my earlier specification referred toabove may be provided with prongs of length at least one quarter themajor axis of the fastener, in a similar manner.

What I claim is:

A fastener comprising a flat strip of spring material bent so as to haveat least a portion of its length in horse- 'shoe'shape with a web andtwo limbs, there being formed intermediate the ends of one limb at leastone prong having its end bent out of the general plane of the materialadjacent the prong so as to be directed outwardly with respect to thehorseshoe and an elongate major portion of the prong between the rootand the said end of the prong which said major portion lies in thegeneral plane of the material adjacent the prong, the maximum width ofthe pronged limb being less than the maximum width of the other limb andthe length of the prong from its root to its end being at least onequarter the length 5 of the major axis of the horseshoe.

References Cited in the file of this patent UNITED STATES PATENTS

